The present invention relates to a continuous coupling having links which form a bogie comprising one or more rotatable bobbins, each bogie being connected to the preceding (or succeeding) bogie by flexible lines which are wound to the bobbins.
There has long been known continuous couplings having links of variable length, which permit the desired speed to be obtained throughout the coupling. Variation in speed is a function of variation in the length of the considered link. Such arrangement is described, for example, in Swiss Patent No. 468292 dated Feb. 15, 1969 (corresponding to U.S. Pat. No. 3,462,002 issued Aug. 19, 1969) and French Patent No. 2236391 dated July 2, 1975 (corresponding to U.S. Pat. No. 4,066,161 issued Jan. 3, 1978).
Such systems are employed in pedestrian and goods transport system and a system of such type is referred to as a semi-continuous system where vehicles decelerate at a station then accelerate.
Different forms of connection are known between the vehicles (cabins or wagons) and the continuous kinematic entrainment coupling. For example, French Patent Application No. 7604526 of Feb. 13, 1976 and U.S. Pat. No. 4,057,017 issued Nov. 8, 197 disclose arrangements in which link length variation is assured by a cable wound on a bobbin carried by a bogie, while the vehicle includes a first part integral with the coupling and a second part connected to a displaceable track. Thus, the second part (or cabin) of each vehicle can be transferred from one location to another by a continuous coupling system comprising several coupling systems.
The present invention provides a novel connection between the vehicle and variable speed continuous coupling to permit the desired speed law to be obtained in the system and to avoid drawbacks in known continuous coupling systems.
One of the main drawbacks is known systems is concerned with the mechanism used to vary the length of the links. This mechanism consists of a wheeled railway system wherein:
the rails are fixed and parallel in the direction of displacement of the coupling; and
the wheels are carried by arms or levers integral with the axis of rotation of a bobbin mounted on a bogie of the coupling and rotatable about its own axis.
On the bobbins are wound flexible lines arranged between successive lines of the coupling. The output of the line is controlled by the rotation of the bobbins, i.e., by the inclination of the rail along the path of displacement of the bogies, along a closed path.
When a bobbin rotates too quickly (its rotation is defined by the rolling sliding of its wheel or wheels on the corresponding fixed rail) relative to the speed of movement of the bogie, the said wheel tends to rotate backwards on its inclined rail, at least during a certain period of its rotation. One then observes a phenomenon called "interference" which is indicated by unexpected variations of acceleration. In the transport systems, the vehicles are thus subjected to jerks so that the comfort of the passengers is disturbed. For example, if the rail descends, its slope opposes contra-rotation of the wheel.
There is known to exist the following possible solutions to reduce this interference phenomenon;
(a) the length of the arms carrying the wheels can be reduced so as to reduce the contra-rotation. To obtain a satisfactory result, the lever arm being too weak, there is introduced into the system excessive forces.
(b) by multiplying the number of bogies, the speed of rotation of the bobbins can be limited for a given advance of the coupling. However, this system is costly, heavy and its reliability is diminished.
(c) two bobbins can be mounted on each bogie. These independent bogies limit considerably the speed laws to be obtained without excessively long rails.